Re: [Kamailio-Users] [Sip-implementors] Secure VoIP

On Thu, Feb 26, 2009 at 5:08 PM, Iñaki Baz Castillo <ibc(a)aliax.net> wrote: We use SRV extensivly, and indeed as the main means of redundancy. However, there are lots of issues with UA implementations of SRV, most notably when they're behind NAT and jumping between different records. Others will not ever expire it's cache, and stick to the same one. Even 2 months after we removed an RR from SRV, we're still seeing some devices using that proxy (!!). Asterisk is particularly bad at doing SRV, to the point we've had to give it it's own DNS record: http://wiki.voip.co.uk/products/asterisk#asterisk.bugs There are STILL some (mainstream) devices out there that don't support DNS. this means we're forced to give IP addresses to customers, which of course is bad for redundancy and capacity planning. As a result, we've devoted (read: wasted) a lot of time and effort on implementing anycast for our platform rather than rely on devices supporting SRV properly. It works, but it's far from pretty and something we should never have had to have done. I'm not actually sure which is better - devices that don't support SRV, or those that try and implement it but don't get it right :-) On the same note, it's shocking how many devices bail out after receiving a 503 and just give up. Please, implementers: 503 does not mean "never try registering again". I don't see any real complexity in RFC 3263 for a well engineered stack. What do you see as being complex about it? ~ Theo -- Theo Zourzouvillys Chief Technical Officer VoIP.co.uk Sent from: Bicester Oxfordshire United Kingdom.